Disable Color Dither method collection
- Edited
Gleb I have an Intel HD4000 Mac Mini lying around which I can't use due to strain - I will definately give this a try today.
Can I use this code with older versions of MacOS?
Also I am interested to know your story; when did you notice symptoms yourself on Macs or other machines, and how did you find out this kext information?
- Edited
Gleb Id like to try this, but am a bit afraid of ruining my macos and having to reinstall. Im getting treated for heterophoria (which you might also have, ever visited a good optometrist?), Its proven to be connected from my own experience with the treatment, but sometimes not 100% treatable so Id still welcome a technical solution.
- Would there be a chance to write this into a simple app that can be used on the taskbar to switch dithering on/off? Id pay you money for it.
- Wasnt there an app (gfx card) that could force using integrated intel graphics even when photoshop etc. is running?
You can also write me at mjanas555 {that at sign} googlemail {dot} com
diop Please let me know if it indeed helps with symptoms.
Can I use this code with older versions of MacOS?
I think yes. But the final answer depends on the Kext in use. You can list Intel kext's to see if we are using same version. If there are different framebuffers, you can send me framebuffer kext and I can take a look if it has this hidden parameter.
when did you notice symptoms
I got eye strain after 3-4 months of using MacBook pro. It became worse when I changed lights in my apartment to PWM led strips. Now I do not use LED lightings, just old lightbulb, and desk lamp. Also, I switched my primary screen from MacBook screen to external Displays (Dell UP2414q). Not starring all day into MacBook screen seems to give me relief.
Never had any problems with most screens for 20 years. Only some crappy glossy PWM displays made me uncomfortable, but I avoided them with success.
how did you find out this kext information?
You need some sort of decompiler. I Use IDA64 with hex-rays plugin.
Then I went into each suspicious Kext (Show content) and pulled binary into IDA64. You are interested to decompile Unix Executable in *.kext/Contents/MacOS/:
https://ibb.co/JCRx1TY
Then in IDA - View->Open Subview->Strings (Shift+F12)
And try to search for Dither there. x key on the string will show all code usages for this string. Go there and press F5 for hex-rays C-like decompiled code
martin Yesterday I screw up with AMD driver modification (every time I set CFG_NO_DITH - I can't restart machine anymore, stuck on logo, about 70%)
The way to fix is to load in recovery mode (holding command+R) and copy unmodified kexts from recovery partiyion to your /System/Library/Extensions/
Here I did screenshot of commands I use for restoring original kext:
https://ibb.co/Gt0X1YH
Gleb I cant even get the first command in terminal running - kextstat | grep Intel
Martin-MacBook-Pro:~ martinjanas$ kexstat | grep Intel
-bash: kexstat: command not found
You are probably very experienced and so certain things seem as given, is there more dumbed down version of how to do this?
Also how about installing windows 10 via bootcamp and trying to disable all of it there to see if it indeed helps your eyes? Could you do that and share the process? Its good testing ground as its easy to wipe it if it goes wrong and still keep macos intact. If it works there, then its good motivation to figure it out for macos.
- Edited
kextstat | grep Intel
That was a typo somewhere
Windows
I do not have much free space currently for it. But even in MacOS flipping integrated\discrete card switch makes a HUGE difference in how fonts and colors looks. Also now it is relaxing on eyes (my gf also see a difference with and without dithering)
- Edited
Gleb Okay so I've got the Mac powered on - disabled csrutil first then restarted.
My drivers loaded look quite different - https://imgur.com/uKdcGfz
- Edited
diop Unfortunately I do not see this hidden parameter for FramebufferCapri:
You may try to set Dither instead of mine DitherDisable
number = 0 to disable it, if I understood Framebuffer code correctly
But I can't promise results. Still worth trying.
In the meantime, I wonder if you install SwitchResX https://www.madrau.com/srx_download/download.html
And reduce colors to Millions of color, instead of billions https://ibb.co/44P4CDQ
AND, more important, in System Preferences -> Display -> Color, select Generic RGB Profile instead of Color LCD https://ibb.co/hXz3JmG
Then it seems to disable (or at least reduce) dithering effects.
You can verify it on gradient image http://www.lagom.nl/lcd-test/gradient.php
It should look banded, not linear gradient as here: https://ibb.co/PY4PZ71
Can you try it and share the experience?
Gleb So initially after trying to follow the instructions I realised I didn't have Xcode installed. I tried to download from the App Store but it required that I upgraded AppleOS. So I've upgraded the system to latest Catalina.
The Grep | Intel list looks the same > https://imgur.com/jjJorY8
However when trying to allow permissions to the Directory/plist file it said something to the effect of 'read only directory'. I ran csr disable in recovery after the Catalina upgrade, so maybe there's another security feature that needs to be disabled first?
I opened the plist file direct in Xcode here > https://imgur.com/HwYyZkD - but I couldn't find any FeatureControl option.
I did change the colour profile to Standard RGB, but didn't install SwitchResX.
Here is a pic of the test page > https://imgur.com/JLWqC1B - I can see a gradient which is strange.
If there's anything you can suggest I will give it a shot - thanks for your help so far. (Glad to know it's working for you at least).
- Edited
diop
You need to navigate deep in that plist file: IOKitPersonalities->AppleIntelFramebufferController->FeatureControl
FeatureControl is a sub-section 3 layer depth from the root. See my picture again: https://ibb.co/dgqK0MS
For the file permissions, you may try right-clicking on plist in finder->get info 
And add your account to this list
fyi.. with AMD+Displayport you can turn off dithering in the control panel (select 6 bit color)
Gleb After a bit of searching online it appears that from Catalina onwards kexts have to be signed by Apple in order to work, also I think the file system changes mean system files are permanently read-only regardless of SIP being switched off.
I downgraded to Mojave and installed Xcode - I made a slight mistake editing the plist and couldn't see a way to undo changes (doh) so will start over tomorrow and try again. Presumably I right-click FeatureControl and 'Add Row'? Then enter the details like you mentioned 'Dither' value '0'.
Do the changes happen immediately after adding the line or does the system need to be restarted first?